Calculation Of Risk Index Research Articles

Transient Operation Risk Assessment of Power System with Wind Farm Integration Based on Dynamic Security Region

With continuous expansion of the grid, the power system structure is becoming more complicated, leading to more and more uncertainty of the system. Especially, the massive integration of wind power and other renewable energy to the grid brings more challenges. In this paper, by taking use of DSR (dynamic security region) and risk assessment theory, it proposed the transient risk index calculation and integrated analysis method for wind power integration system, which was able to give quantitative indicators of the system day-ahead scheduling plan. The efficiency and practicality of theories mentioned herein were verified by standard numerical examples.

Concentrations and Health Risk Assessments of Heavy Metals in Fish from the Fosu Lagoon

Concentrations of Cu, Pb, Cr, Cd, Mn, Ni, Fe and Zn were determined in the muscle samples of Sarotherodon melanotheron from the Fosu Lagoon in Cape Coast using atomic absorption spectrophotometer. The results showed that, metal concentration in the fish muscle was in the order Mn > Zn > Fe > Pb > Ni > Cd > Cu > Cr. Mean concentrations of Pb and Cd in the fish exceeded the maximum tolerable limit set by the European Union. Although the mean concentrations of some metals exceeded this limit, their estimated daily intakes were below their oral reference dose recommended by the international regulatory bodies. Health risk assessment of consumers from the intake of metal contaminated in the muscle of S. melanotheron from the lagoon was evaluated by using Health Risk Index (HRI) calculations. In this study, the total HRI through consumption of fish calculated by adding the individual HRIs was less than 1, indicating that there is no significant potential health risk associated with the consumption of fish from the Fosu Lagoon.

Fluoride hazard and assessment of groundwater quality in the semi-arid Upper Panda River basin, Sonbhadra district, Uttar Pradesh, India

Around 9000 inhabitants in the Panda River basin, Sonbhadhra District, Uttar Pradesh, India, are vulnerable to a “silent” dental and skeletal fluorosis from groundwater consumption. The fluoride source and seasonal groundwater quality variation were studied by collecting 65 groundwater samples in the Upper Panda River basin. Major rock types are phyllites and granite gneissic rocks. Fluoride concentrations are in the range 0.4–5.6 mg/L in the pre-monsoon season and 0.1–6.7 mg/L in the post-monsoon season. Fluor-apatite and biotite mica in the granite gneissic rock were identified as the main provenance of fluoride in the groundwater through water–rock interactions. Due to precipitation of calcium, soils become alkaline with high contents of sodium; these conditions allow fluoride to accumulate in water. According to risk index calculations, the fluoride-affected villages were shown to fall in the fluoride risk zone (with a risk index of around 1.7). On the basis of mineral stability diagrams, groundwater from the weathered and fractured aquifers appears to be stable within the kaolinite field, suggesting weathering of silicate minerals. The groundwater is chemically potable and suitable for domestic and agricultural purposes, except for a few wells in the southern region that are contaminated with high amounts of fluoride. Editor D. Koutsoyiannis Citation Raju, N.J., Dey, S., Gossel, W., and Wycisk, P., 2012. Fluoride hazard and assessment of groundwater quality in the semi-arid Upper Panda River basin, Sonbhadra District, Uttar Pradesh, India. Hydrological Sciences Journal, 57 (7), 1433–1452.

Delimitation of kala-azar risk areas in the district of Vaishali in Bihar (India) using a geo-environmental approach

Remote sensing and geographical information technologies were used to discriminate areas of high and low risk for contracting kala-azar or visceral leishmaniasis. Satellite data were digitally processed to generate maps of land cover and spectral indices, such as the normalised difference vegetation index and wetness index. To map estimated vector abundance and indoor climate data, local polynomial interpolations were used based on the weightage values. Attribute layers were prepared based on illiteracy and the unemployed proportion of the population and associated with village boundaries. Pearson's correlation coefficient was used to estimate the relationship between environmental variables and disease incidence across the study area. The cell values for each input raster in the analysis were assigned values from the evaluation scale. Simple weighting/ratings based on the degree of favourable conditions for kala-azar transmission were used for all the variables, leading to geo-environmental risk model. Variables such as, land use/land cover, vegetation conditions, surface dampness, the indoor climate, illiteracy rates and the size of the unemployed population were considered for inclusion in the geo-environmental kala-azar risk model. The risk model was stratified into areas of "risk"and "non-risk"for the disease, based on calculation of risk indices. The described approach constitutes a promising tool for microlevel kala-azar surveillance and aids in directing control efforts.

Temporary risk identification in urolithiasis

We have been using a risk index calculation for urolithiasis, which included most of the identifiable factors promoting calculogenesis. However, it was observed that the frequency of a patient getting stone problem was not uniform in spite of similarity of the risk index in the permanent setting. Also, many of the risk indices could be changed by dietary or lifestyle modifications. The objective of this paper was to calculate the temporary risk index of a patient at the time of each visit and correlate with stone activity during such periods, so that appropriate advice could be given on drugs, diet and lifestyle changes. The temporary risk index score was based on four symptoms, namely pain (0, nil; 1, vague pain; 2, mild; 3, moderate; 4, severe; 5, excruciating), haematuria (0, nil; 1, turbid; 2, cloudy; 3, reddish; 4, occasional frank blood; 5, continuous frank blood), burning sensation (0, nil; 1, minimal; 2, moderate; 3, terminal severe; 4, occasional excruciating; 5, continuous excruciating), and dysuria (0, nil; 1, minimal; 2, moderate; 3, terminal severe; 4, occasional excruciating, 5, continuous excruciating), ultrasonography for back pressure (0, nil; 1, mild; 2, moderate; 3, severe kidney and ureter; 4, unilateral total; 5, bilateral total anuria) and eight urine deposit findings (0, nil; 1, +; 2, 2+; 3, 3+; 4, 4+; 5, plenty), red blood cells, pus cells, whewellite crystals, weddellite crystals, phosphate crystals, uric acid/ammonium urate crystals, crystal clumping and crystal aggregation making a total of 13 parameters. Each parameter was given values ranging from 0 to 5. The total score was calculated and chemotherapeutic regimes were decided base on the score, which varied from 0 to 65. Hundred randomly selected patients who had been visiting the stone clinic for a minimum of five occasions were included in the study. The total scores of temporary risk were correlated with the permanent clinical risk score mentioned earlier. The temporary risk of the 100 patients during the total of 500 visits ranged from 0 to 43 out of 65. The risk score reduced significantly from visit 1 to 5 in all the patients. On correlating the mean index of the five visits with the permanent risk index, the correlation coefficient r value was +0.39 (P < 0.01). It was observed that patients go through periods of hyperactivity of stone metabolism and present with symptoms, producing temporary phases of overactivity. It is concluded that temporary risk index is correlatable with the permanent risk index of the patients forming urinary stones. It can be used as a method for scientific prediction regarding future stone formation in any individual. The dose of drugs and need for continuing chemotherapy for patients should be based on the temporary risk index. The blind prescription of drugs should be discouraged.

Optimal Use of Re-Excision in Patients Diagnosed with Early-Stage Breast Cancer by Excisional Biopsy Treated with Breast-Conserving Therapy

The goal of the current study is to help refine guidelines for the need for re-excision and the appropriate amount of breast tissue to re-excise in patients with early breast cancer following excisional breast biopsy when treated with breast-conserving therapy (BCT). The study population consisted of 441 patients derived from a dataset of 607 consecutive cases of stage I and II breast cancer treated with BCT, in which patients underwent primary excisional diagnostic biopsy and subsequent re-excision prior to the initiation of radiation therapy (RT). A single pathologist reviewed all specimens. Re-excision was indicated because tumor was found close to or involving the resection margin. In 333 of the 441 cases, it was possible to measure the extension of carcinoma into the re-excision specimen. Margins were classified as negative (carcinoma>4.2 mm from the margin), near (<4.2 mm from the margin) or positive. Any carcinoma identified near the final margin was quantified by width of invasive carcinoma and number of ductal carcinoma in situ (DCIS) ducts near the margin and subdivided into three distinct groups: least, intermediate, and greatest amount. These factors were then analyzed to determine the likelihood and extent of residual carcinoma in re-excision specimens. Statistical analysis was performed using Systat version 10 (SPSS Inc., Chicago, IL). The quantity of carcinoma near the initial biopsy margin and the invasive carcinoma-to-specimen dimension ratio demonstrated a significant association with increasing amounts of residual carcinoma at re-excision. Combination of these two variables allowed for a statistically significant (P<0.001) calculation of risk index for identifying significant residual invasive carcinoma or DCIS in the adjacent breast parenchyma at re-excision, and yielded stratification into low- (6%), intermediate- (27%), and high-risk (44%) groups. In re-excision specimens, the observed distance of carcinoma extension into adjacent breast tissue was associated with a statistically significant decrease in the ratio of the initial excisional biopsy specimen dimensions and invasive carcinoma dimensions. Combining the initial margin status with the specimen-to-invasive carcinoma maximum dimension ratio yielded an accurate predictor of the maximum distance of tumor extension. Evaluation of the initial excisional biopsy margin status in correlation with the invasive carcinoma-to-specimen maximum dimension ratio may be helpful for (1) identifying patients who require re-excision prior to RT and (2) predicting the quantity of additional breast tissue to excise to ensure adequate surgical margins with BCT.

The national nosocomial surveillance network in Hungary: results of two years of surgical site infection surveillance

In 2004, a secure web-based national nosocomial infection surveillance system was established in Hungary. The system, named NNSR (Nemzeti Nosocomiális Surveillance Rendszer), is based on the US National Nosocomial Infection Surveillance System (NNIS). Surgical procedures, definitions, surveillance methodology and patient risk indices are those established by NNIS. In this paper, we present the results of the first two years of the surgical patient component of our system. During this period, 41 hospitals participated and selected 11 surgical procedures for surveillance. Altogether 15812 procedures were surveyed and 360 resulting surgical site infections (SSI) were recorded. The overall SSI rate was 2.27%. The most commonly selected procedures and corresponding SSI rates were caesarean section (1.31%), herniorrhaphy (2.09%), cholecystectomy (1.52%) and hip replacement (2.91%). Standardised infection ratios (SIR) were calculated for chosen surgical procedures in order to compare against NNIS published rates. SSI rates for colonic surgery, caesarean section and mastectomy were lower than expected according to the NNIS data but higher for cholecystectomy, herniorrhaphy and hip prosthesis infection rates. We intend to recruit more participating hospitals, leading to a robust national database that can be used to target infection control interventions for patients in Hungary.

Gastric Bypass is not Associated with Protein Malnutrition in Morbidly Obese Patients

Patients undergoing bariatric surgery with a gastric bypass lose about 66% of excess weight. Although this procedure induces weight loss, it is unknown whether it leads to protein malnutrition, which is studied here. One hundred ten obese patients (body mass index, 47.9 +/- 8.6 kg/m(2)) undergoing gastric bypass had a measurement of plasma albumin and transthyretin (formerly prealbumin) and a calculation of nutritional risk index (NRI) before and throughout the 2 years following the surgery. All but five patients lost more than 15% of initial weight; the mean loss of excess weight was 65.2 +/- 26.4% at 2 years. Plasma concentrations of albumin and transthyretin decreased after surgery, but while albumin returned to initial values after 12 months, transthyretin remained low. Only one patient had an albumin below 30 g/l; another one had a transthyretin lower than 110 mg/l. All NRI scores were lower than 83.5 (62 +/- 5, ranging 44-70), qualifying patients for severe malnutrition. Malnutrition is difficult to diagnose in obese patients undergoing surgery. The large weight loss is most often not associated with protein malnutrition. Whether gastric bypass induces protein malnutrition remains to be established.

Ambient Levels of Primary and Secondary Pollutants in a Residential Area: Population Risk and Hazard Index Calculation over a Three Years Study Period

This paper aims at presenting data collected over the period of three years (2004-2006) in a residential area in the state of Kuwait. The data collected include ambient levels of primary and secondary pollutants with a number of metrological parameters. A series of unfiltered and filtered concentration roses were plotted to determine the predominant sources as well as the prevailing winds affecting the area under investigation. Local and international air quality regulations were cross referenced over the course of this study. The main objective was to determine whether this residential area could be considered as a safe site for further urban estate development and the risk of the population residing exposed to carcinogens in the ambient air. Although the hazard index values were within the safe range, the population affected with cancer due to benzene inhalation was increasing based on cancer risk assessment calculations.

Problems in the investigation of urine from patients suffering from primary hyperoxaluria type 1

Regular calculation of urinary crystallization risk indices in patients suffering from urolithiasis is a recommended measure for treatment adjustment. The more the patient experiences either extensive stone formation or an enhanced recurrence rate, the more important risk index calculations. In patients suffering from primary hyperoxaluria type 1 (PH1), both criteria are met. Different methods of risk determination are known. All strategies for measuring the calcium oxalate (CaOx) crystallization risk of a given urine principally determine this parameter from voided urine. This "bladder urine", however, has possibly passed stone material located in the urinary tract and thus may be depleted in lithogenic components. This is commonly the case for patients with PH1, who mostly experience a massive stone burden or severe nephrocalcinosis. Hence, the question arises as to whether we can adequately determine the crystallization risk in the urine of stone-bearing PH1-patients or not. Based on model calculations, we show that the determination of CaOx formation risk in PH1-patients requires knowledge of the restrictions in risk index interpretation: risk indices calculated from urinalysis (e.g. EQUIL) still indicate, even after strong in vivo stone formation, an enhanced but in fact strongly underestimated risk value. However, the outcome "enhanced" masks the patient's true risk situation. The BONN Risk Index (BRI), in contrast, discloses the process of extreme in vivo crystal formation. As determined, inter alia, from the urinary concentration of free ionized calcium ([Ca(2+)]), BRI approaches abnormally low values, as, in consequence of CaOx - formation, [Ca(2+)] tends to values close to zero. Thus, calculations of urinalysis-based risk indices alone are insufficient strategies for the quantification of a PH1 patient's CaOx crystallization risk.

Using calorimetry for determining the risk indices to prevent and fight forest fires

A method is proposed for calculation of risk indices of different forest formations existing in Galicia. These values are helpful to predict the behaviour of forest species in case of forest fires and thus to prevent and/or fight these wildfires. Main parameters for calculation of risk indices are calorific values measured by bomb calorimetry and flammability measured by a standard epiradiator. These parameters were studied together with chemical analysis of different forest samples and an intensive research of physical and environmental parameters. All the data presented were determined in the last 10 years in Galicia (NW of Spain).

Calculation of risk and statistical indices associated with available transfer capability

A complete evaluation of available transfer capability (ATC) involves the determination of total transfer capability (TTC), transmission reliability margin (TRM) and capacity benefit margin (CBM). Due to the stochastic nature of power system behaviour, which is considered by TRM, it is important to assess ATC from a statistical and risk analysis point of view. Based on a combination of repeated AC power flow and Monte Carlo methods, risk assessment of the ATC value is described and a set of statistical indices and plots is presented, which provides important information for transmission customers, system operators and power marketers. In addition, two methods of incorporating CBM into ATC are presented and compared. Case studies with the IEEE Reliability Test System (RTS) demonstrate the effectiveness of the proposed methods, indices and plots. The impact of uncertainty, CBM and methods of incorporating CBM on ATC are also investigated.

A Human Health Risk Assessment of Pharmaceuticals in the Aquatic Environment

Analyses were conducted on four pharmaceutical compounds, representing different therapeutic classes, to evaluate the presence and potential adverse human health effects of trace levels of these substances in aqueous environmental media. Acetylsalicylic acid, clofibrate, cyclophosphamide, and indomethacin have been detected in aqueous environmental media including sewage treatment plant effluent, surface water, drinking water, and groundwater. An extensive literature search and chemical-specific risk assessments were performed to assess the potential human health significance of each compound's individual presence in environmental media. Safe water quality limits were estimated for each pharmaceutical by following the USEPA Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health and were compared to the concentrations found in the environment. The calculation of the provisional ambient water quality criteria involved estimation of human exposure to contaminated water, including intake via bioaccumulation in fish, and calculation of cancer risk and non-cancer hazard indices. Parameters detailing the toxicological and pharmacological nature, exposure assessment, and environmental fate and transport of each pharmaceutical were also considered. The overall conclusion was that based on available data, no appreciable risk to humans exists, as the detected concentrations of each of these pharmaceutical compounds found in aqueous media were far below the derived safe limits

A Human Health Risk Assessment of Pharmaceuticals in the Aquatic Environment

Analyses were conducted on four pharmaceutical compounds, representing different therapeutic classes, to evaluate the presence and potential adverse human health effects of trace levels of these substances in aqueous environmental media. Acetylsalicylic acid, clofibrate, cyclophosphamide, and indomethacin have been detected in aqueous environmental media including sewage treatment plant effluent, surface water, drinking water, and groundwater. An extensive literature search and chemical-specific risk assessments were performed to assess the potential human health significance of each compound's individual presence in environmental media. Safe water quality limits were estimated for each pharmaceutical by following the USEPA Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health and were compared to the concentrations found in the environment. The calculation of the provisional ambient water quality criteria involved estimation of human exposure to contaminated water, including intake via bioaccumulation in fish, and calculation of cancer risk and non-cancer hazard indices. Parameters detailing the toxicological and pharmacological nature, exposure assessment, and environmental fate and transport of each pharmaceutical were also considered. The overall conclusion was that based on available data, no appreciable risk to humans exists, as the detected concentrations of each of these pharmaceutical compounds found in aqueous media were far below the derived safe limits

Using bomb calorimetry for determination of risk indices of wildfires originating from pine residues

Pine trees, mainly Pinus pinaster Aiton, now cover 640,000 ha of the forest occupied surface in Galicia. The possibility of using the residues originating from pine tree exploitation as an alternative energy source could yield to gross benefit around 2.8×10 8 euros per year, together with ecological advantages. The object of the present study is the evaluation of the energy contained in these residues through the measurement of their caloric values using a static bomb calorimeter. At the same time, flammabilities were measured by a standard epiradiator thus allowing the calculation of risk indices. This latter is very important to fight and prevent the start and spreading of forest fires. Elementary chemical composition was also determined using an elementary chemical analyser. Biological and bioclimatic parameters, which are very useful for the evaluation of caloric values and flammabilities over the year, were used for discussion of results.

Calculation of forest biomass indices as a tool to fight forest fires

Wildfires are mainly responsible for economical and ecological disasters both in forests and forest resources all over the world. In this article, we report a method which allows the calculation of risk indices to be used in campaigns designed for preventing and/or fighting forest fires. The method is based on the determination of calorific values using a static bomb calorimeter in oxygen atmosphere following the procedure given by Hubbard et al. [in: F.D. Rossini (Ed.), Experimental Thermochemistry, Interscience Publishers, New York, 1956, p. 5] and flammabilities using the method proposed by Valette [Documentos del seminario sobre métodos y equipos para la prevención de incendios forestales, ICONA, Madrid, 1988]. A combined study of thermochemical data and bioclimatic parameters allowed the calculation of risk indices for the different species making up the forest vegetation of a zone situated in the coast of Galicia (NW Spain). These risk indices can be presented in the form of maps and, thus, be used to prevent and/or fight forest fires.

Design of risk index maps as a tool to prevent forest fires in the humid Atlantic zone of Galicia (NW Spain)

In previous articles, we set the basis for the determination of risk indices of forest biomass of Galicia. With this aim, calorific values, flammability, density, moisture contents, ash percentage after combustion, elementary chemical composition, and heavy metal contents over the seasons of the year for the different species which make up the woodland map of a given zone were determined. In the present paper, these studies were applied to this humid Atlantic zone situated in Galicia (NW Spain). The special climatic characteristics of the humid Atlantic zone chosen for our study make its vegetal community singularly gifted. The calorific values of combustion at 25°C were measured by static bomb calorimetry for the different forest species existing in the zone. These data were complemented with flammability values, measured by an epiradiator and completed with chemical analyzes. Some biological and climatic properties necessary for our calculations were taken from available literature. A combined study of all these parameters led to calculation of risk indices of the forest species of the zone over the year. The knowledge of the seasonal risk indices can be very helpful to prevent and fight forest fires effectively, and also for a rational management and exploitation of the forest resources through the obtention of xyloenergy.

Coal Workers’ Pneumoconiosis and Related Risk Indices

Coal Workers’ Pneumoconiosis and Related Risk Indices: Qiao Niu, et al. Department of Public Health, Shanxi Medical College—Cross sectional epidemiological studies were carried out in three coal mines (Mines A, B and C), that produce differnt types of coal in order to examine the relationship between the prevalence of coal workers’ pneumoconiosis (CWP) and factors contributing to the development and seriousness of CWP. Seven factors were taken into consideration and two of them were calculated as “risk indices”. They concerned composition (including carbon, ash, volatile content of coal, free silica in coal dust and rock dust) and exposure factors (including dust concentration, duration of exposure and type of operation). Composition factors were: carbon 90%, ash 23.13%, volatile content 13.85%, free silica in coal dusts 2.58% and free silica in rock dusts 32.88% in Mine A. Carbon 82%, ash 8%, volatile content 28.5%, free silica in coal dusts 5.90% and free silica in rock dusts 33.0% in Mine B. Carbon 94%, ash 20.46%, volatile content 10.76%, free silica in coal dusts 2.04% and free silica in rock dusts 24.04% in Mine C. Differences in the coal dust concentration over a period of 20 to 30 years were not significant in the three mines. The rock dust concentration in Mine B was much higher than those in the other two mines. The CWP prevalence was 2.22% in Mine A, 13.20% in Mine B and 1.86% in Mine C. Analysis has shown that both composition and exposure factors were related to CWP prevalence, but the strength of the relationship between the factors was different in the three mines, especially in Mine B, where there was a high CWP prevalence, and the association of CWP with free silica and high volatile content was strong. It was interesting that, though the rank of coal in Mine B was much lower than those in Mine A and Mine C, the prevalence of CWP in Mine B was much higher than those in Mine A and Mine C. This result was in contrast with those reported before. The calculation of risk indices indicated that there was a positive correlation between the risk indices and exposure duration.

The risk profile of the glaucomatous patient

This article briefly overviews risk factors involved in the multifactorial glaucomatous disease such as hypotension, preexisting field damage, location of scotomas, intraocular pressure, vasospasm, vasoactive agents, and less connective tissue of the optic disc. We summarize some of these risk factors in a formula allowing the calculation of a glaucoma progression risk index. This index helps to identify patients who are at risk for further visual field deterioration already at the time of the initial perimetric examination. Diagnostic and therapeutic aspects are highlighted.

The use of tracers to estimate the exposure of beneficial insects to direct pesticide spraying in cereals

SummaryA fluorescent spray tracer was used to measure the profile of spray deposits through winter‐wheat crop canopies and upon beneficial insects, placed in fixed positions which approximated to their natural distributions. Tracer deposition profiles were recorded on a series of occasions between G.S. 47 to G.S. 90. Deposition levels declined through the canopy on each occasion but the proportion of the spray reaching the ground varied between growth stages. Deposition rates upon insects followed the same trends but insects on the aerial parts of the plant received a higher volume of tracer per unit area than the part of the crop that they were placed upon. Insects placed on the ground received a dose equivalent to their ground area. For a given distribution of insects, these data permit direct spray exposure to be estimated. The general application of the method to a wide range of crops, to the calculation of risk indices, to the standardisation of field tests and to the development of selective spray placement methods are discussed.